{"id":"CVE-2022-39369","aliases":["DEBIAN-CVE-2022-39369","DLA-3485-1","EUVD-2022-7285","GHSA-8q72-6qq8-xv64","MGASA-2022-0432","UBUNTU-CVE-2022-39369","USN-6913-1","USN-6913-2","USN-6914-1"],"status":"published","title":"Service Hostname Discovery Exploitation in phpCAS","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","severity":{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.02433,"percentile":0.84492,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1287","CWE-99"],"published":"2022-11-01T00:00:00Z","modified":"2026-10-28T02:30:58Z","fixes":[{"ecosystem":"Packagist","package":"apereo/phpcas","fixed_in":["1.6.0"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"php-cas","fixed_in":["1.6.0-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"php-cas","fixed_in":["1.6.0-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"php-cas","fixed_in":["1.6.0-1"],"sources":["osv"]},{"ecosystem":"Debian:10","package":"php-cas","fixed_in":["1.3.6-1+deb10u1"],"sources":["osv"]},{"ecosystem":"Mageia:8","package":"php-pear-CAS","fixed_in":["1.6.0-1.mga8"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:16.04:LTS","package":"php-cas","fixed_in":["1.3.3-2ubuntu1+esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:20.04:LTS","package":"php-cas","fixed_in":["1.3.8-1ubuntu0.20.04.1"],"sources":["osv"]},{"ecosystem":"Ubuntu:22.04:LTS","package":"ocsinventory-server","fixed_in":["2.8.1+dfsg1-1ubuntu0.1"],"sources":["osv"]},{"ecosystem":"Ubuntu:22.04:LTS","package":"php-cas","fixed_in":["1.3.8-1ubuntu0.22.04.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"apereo/phpcas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.0-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.0-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.0-1"}]}]},{"source":"osv","ecosystem":"Debian:10","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.6-1+deb10u1"}]}],"versions":["1.3.6-1"]},{"source":"osv","ecosystem":"Packagist","package":"apereo/phpcas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.0"}]}],"versions":["1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.3.8","1.3.9","1.4.0","1.5.0"]},{"source":"osv","ecosystem":"Mageia:8","package":"php-pear-CAS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.0-1.mga8"}]}]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.3-2ubuntu1+esm1"}]}],"versions":["1.3.3-1","1.3.3-2","1.3.3-2ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.9+dfsg-1","2.7.10+dfsg-1","2.7.11+dfsg-1","2.7.11+dfsg-2","2.7.12+dfsg-1","3.0.3+dfsg-0ubuntu1","3.0.3+dfsg-0ubuntu1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"ocsinventory-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.2-1","2.1.2-1ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.3+dfsg-0ubuntu1","3.0.3+dfsg-0ubuntu1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.3-4"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.8-1ubuntu0.20.04.1"}]}],"versions":["1.3.6-1","1.3.8-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"ocsinventory-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.1+dfsg1-1ubuntu0.1"}]}],"versions":["2.8.1+dfsg1-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.8-1ubuntu0.22.04.1"}]}],"versions":["1.3.8-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.8-1ubuntu0.20.04.1"}]}],"versions":["1.3.6-1","1.3.8-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.8-1ubuntu0.22.04.1"}]}],"versions":["1.3.8-1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"php-cas","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.3-2ubuntu1+esm1"}]}],"versions":["1.3.3-1","1.3.3-2","1.3.3-2ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"ocsinventory-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.1+dfsg1-1ubuntu0.1"}]}],"versions":["2.8.1+dfsg1-1"]}],"products":[{"vendor":"apereo","product":"phpcas"},{"vendor":"fedoraproject","product":"fedora"}],"references":[{"url":"https://github.com/apereo/phpCAS/security/advisories/GHSA-8q72-6qq8-xv64","tags":["x_transferred","Mitigation","Third Party Advisory","advisory","web","report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RUA2JM6YT3ZXSZLBJVRA32AXYM3GJMO3/","tags":["vendor-advisory","x_transferred","advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2XL7SMW6ESSP2Y6HHRYWW2MMCZSI4LBZ/","tags":["vendor-advisory","x_transferred","advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VJZGTWJ5ZXUUT47EHARNOUUNTH6SYDSE/","tags":["vendor-advisory","x_transferred","advisory"]},{"url":"https://lists.debian.org/debian-lts-announce/2023/07/msg00007.html","tags":["mailing-list","x_transferred","article","web"]},{"url":"https://github.com/apereo/phpCAS/commit/b759361d904a2cb2a3bcee9411fc348cfde5d163","tags":["web"]},{"url":"https://github.com/apereo/phpCAS/releases/tag/1.6.0","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2022-39369","tags":["advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2XL7SMW6ESSP2Y6HHRYWW2MMCZSI4LBZ/"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RUA2JM6YT3ZXSZLBJVRA32AXYM3GJMO3/"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VJZGTWJ5ZXUUT47EHARNOUUNTH6SYDSE/"},{"url":"https://github.com/advisories/GHSA-8q72-6qq8-xv64","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39369.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2022-39369","tags":["advisory"]},{"url":"https://github.com/apereo/phpCAS","tags":["package"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2XL7SMW6ESSP2Y6HHRYWW2MMCZSI4LBZ","tags":["web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RUA2JM6YT3ZXSZLBJVRA32AXYM3GJMO3","tags":["web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VJZGTWJ5ZXUUT47EHARNOUUNTH6SYDSE","tags":["web"]},{"url":"https://advisories.mageia.org/MGASA-2022-0432.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=31110","tags":["report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/2XL7SMW6ESSP2Y6HHRYWW2MMCZSI4LBZ/","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2022-39369","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2022-39369","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-6914-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/notices/USN-6913-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/notices/USN-6913-2","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2022-39369","title":"Service Hostname Discovery Exploitation in phpCAS","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","status":"published","published":"2022-11-01T00:00:00Z","modified":"2025-04-23T16:41:58.291Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-99","CWE-1287"],"updated_at":"2026-11-02T14:34:39.559326Z"}],"euvd":[{"id":"EUVD-2022-7285","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","status":"published","published":"2022-11-01T00:00:00Z","modified":"2025-04-23T16:41:58Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T20:52:11.891054Z"}],"ghsa":[{"id":"GHSA-8q72-6qq8-xv64","title":"phpCAS vulnerable to Service Hostname Discovery Exploitation","description":"### Impact\n\nThe phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. \nDepending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied.\n\nThis vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. \n\n### Patch\n\nphpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class.\n\nFor more information, please refer to the upgrading doc.\n\n### Workarounds\n\nThis vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup:\n\n1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and\n2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled.\n3. Alternatively, if your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability.\n\nOtherwise, you should upgrade the library to get the safe service discovery behavior.\n\nIf your CAS server service registry is configured to only allow known and trusted service URLs, the severity of the vulnerability is reduced substantially since an attacker must be in control of another authorized service.\n\n### Acknowledgement\n\nWe would like to thank Filip Hejsek for discovering this vulnerability, responsibly reporting it to the developers, and helping harden the patch.\n\nHenry Pan and Joachim Fritschi helped with the patch and release effort as phpCAS developers.","status":"published","published":"2022-11-01T18:11:07Z","modified":"2023-07-10T19:02:07Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-1287"],"updated_at":"2026-11-02T14:36:56.605555Z"}],"nvd":[{"id":"CVE-2022-39369","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","status":"published","published":"2022-11-01T17:15:10.267Z","modified":"2026-06-17T04:58:13.79Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-99","CWE-1287"],"updated_at":"2026-11-02T14:07:31.504574Z"}],"osv":[{"id":"CVE-2022-39369","title":"Service Hostname Discovery Exploitation in phpCAS","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","status":"published","published":"2022-11-01T00:00:00Z","modified":"2026-10-28T02:30:58.295529838Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-1287","CWE-99"],"updated_at":"2026-11-02T15:44:26.860704Z"},{"id":"DEBIAN-CVE-2022-39369","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","status":"published","published":"2022-11-01T17:15:10.267Z","modified":"2026-11-03T08:03:05.588014122Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T08:24:39.643572Z"},{"id":"GHSA-8q72-6qq8-xv64","title":"phpCAS vulnerable to Service Hostname Discovery Exploitation","description":"### Impact\n\nThe phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. \nDepending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied.\n\nThis vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. \n\n### Patch\n\nphpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class.\n\nFor more information, please refer to the upgrading doc.\n\n### Workarounds\n\nThis vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup:\n\n1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and\n2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled.\n3. Alternatively, if your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability.\n\nOtherwise, you should upgrade the library to get the safe service discovery behavior.\n\nIf your CAS server service registry is configured to only allow known and trusted service URLs, the severity of the vulnerability is reduced substantially since an attacker must be in control of another authorized service.\n\n### Acknowledgement\n\nWe would like to thank Filip Hejsek for discovering this vulnerability, responsibly reporting it to the developers, and helping harden the patch.\n\nHenry Pan and Joachim Fritschi helped with the patch and release effort as phpCAS developers.","status":"published","published":"2022-11-01T18:11:07Z","modified":"2024-02-20T05:51:30.171885Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-1287"],"updated_at":"2026-11-02T15:46:42.78452Z"},{"id":"UBUNTU-CVE-2022-39369","description":"phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central Authentication Service (CAS) server. The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to \"^(https)://.*\") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP. Starting this version, it is required to pass in an additional service base URL argument when constructing the client class. For more information, please refer to the upgrading doc. This vulnerability only impacts the CAS client that the phpCAS library protects against. The problematic service URL discovery behavior in phpCAS \u003c 1.6.0 will only be disabled, and thus you are not impacted from it, if the phpCAS configuration has the following setup: 1. `phpCAS::setUrl()` is called (a reminder that you have to pass in the full URL of the current page, rather than your service base URL), and 2. `phpCAS::setCallbackURL()` is called, only when the proxy mode is enabled. 3. If your PHP's HTTP header input `X-Forwarded-Host`, `X-Forwarded-Server`, `Host`, `X-Forwarded-Proto`, `X-Forwarded-Protocol` is sanitized before reaching PHP (by a reverse proxy, for example), you will not be impacted by this vulnerability either. If your CAS server service registry is configured to only allow known and trusted service URLs the severity of the vulnerability is reduced substantially in its severity since an attacker must be in control of another authorized service. Otherwise, you should upgrade the library to get the safe service discovery behavior.","status":"published","published":"2022-11-01T17:15:00Z","modified":"2026-09-23T18:46:12.863879717Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"},{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T16:53:55.502114Z"},{"id":"DLA-3485-1","title":"php-cas - security update","status":"published","published":"2023-07-08T00:00:00Z","modified":"2026-03-09T01:23:20.059519Z","updated_at":"2026-11-02T15:46:11.734021Z"},{"id":"MGASA-2022-0432","title":"Updated php-pear-CAS packages fix security vulnerability","description":"This update fixes a vulnerability in this lib. For details see\nrefererenced github advisory.\n","status":"published","published":"2022-11-18T22:50:51Z","modified":"2026-04-16T04:42:10.30146791Z","updated_at":"2026-11-02T15:49:42.263076Z"},{"id":"USN-6913-1","title":"php-cas vulnerability","description":"Filip Hejsek discovered that phpCAS was using HTTP headers to determine\nthe service URL used to validate tickets. A remote attacker could\npossibly use this issue to gain access to a victim's account on a\nvulnerable CASified service.\n\nThis security update introduces an incompatible API change. After applying\nthis update, third party applications need to be modified to pass in an\nadditional service base URL argument when constructing the client class.\n\nFor more information please refer to the section\n\"Upgrading 1.5.0 -\u003e 1.6.0\" of the phpCAS upgrading document:\n\nhttps://github.com/apereo/phpCAS/blob/master/docs/Upgrading\n\n","status":"published","published":"2024-07-24T18:45:17Z","modified":"2026-02-10T04:44:41Z","updated_at":"2026-11-02T16:58:17.914523Z"},{"id":"USN-6913-2","title":"php-cas vulnerability","description":"USN-6913-1 fixed CVE-2022-39369 for Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.\nThis update provides the corresponding fix for Ubuntu 16.04 LTS.\n\nOriginal advisory details:\n\nFilip Hejsek discovered that phpCAS was using HTTP headers to determine\nthe service URL used to validate tickets. A remote attacker could\npossibly use this issue to gain access to a victim's account on a\nvulnerable CASified service.\n\nThis security update introduces an incompatible API change. After applying\nthis update, third party applications need to be modified to pass in an\nadditional service base URL argument when constructing the client class.\n\nFor more information please refer to the section\n\"Upgrading 1.5.0 -\u003e 1.6.0\" of the phpCAS upgrading document:\n\nhttps://github.com/apereo/phpCAS/blob/master/docs/Upgrading\n","status":"published","published":"2024-07-31T18:01:51Z","modified":"2026-06-25T13:32:28.702077236Z","updated_at":"2026-11-02T16:58:17.914523Z"},{"id":"USN-6914-1","title":"ocsinventory-server vulnerability","description":"\nFilip Hejsek discovered that the phpCAS library included in OCS Inventory\nwas using HTTP headers to determine the service URL used to validate\ntickets. A remote attacker could possibly use this issue to gain access\nto a victim's account.\n\n","status":"published","published":"2024-07-24T19:22:11Z","modified":"2026-02-10T04:44:41Z","updated_at":"2026-11-02T16:58:17.914523Z"}]}}